1. Field of the Invention
The present invention relates, in general, to a tilt steering apparatus for a vehicle. More specifically, the present invention relates to a tilt steering apparatus for a vehicle, capable of adjusting the angle of a steering column by engaging a movable gear with a fixed gear or disengaging the movable gear from the fixed gear, using a lock slider that does a rectilinear motion by an operation lever.
2. Description of the Related Art
A tilt steering (also called ‘tilt handle’), as the name implies, indicates an inclined steering wheel. In other words, the angle of a steering column can be adjusted according to the physical figure (physique) or driving posture of a driver.
Although the height of the steering wheel is adjusted by manually disengaging a movable gear from a fixed gear using a lever attached to the steering column, an electric steering is also available.
FIG. 1 is a side cross-sectional view of a tilt apparatus in a steering column according to a related art, and FIG. 2 is a bottom view of the tilt apparatus in FIG. 1.
In particular, the tilt apparatus for the steering column shown in these drawings was disclosed in Japanese Patent Publication No. 1999-198821. Referring to the drawings, there is an lower bracket 31 that is attached to the lower portion of the steering column 11 so as to adjust the same, and a fixed gear 31a is formed on the lower portion of the lower bracket 31.
A movable gear 32 is also attached to the lower portion of the lower bracket 31 in such a manner that the movable gear is tooth-locked to the fixed gear 31a and one side thereof is hinged 26, being pivotably movable. A bottom surface 32b of the movable gear is curved.
In addition, a lock slider 33 is attached to the lower portion of the movable gear 32, being combined with an operation lever 34 as one body. The lock slider 33 slides along the bottom surface 32a of the movable gear, to engage/disengage the movable gear 32 to/from the fixed gear 31a. 
FIG. 3 diagrammatically illustrates an operational state of the related art tilt apparatus for the steering column.
As depicted in FIG. 3, if the operation lever 34 pivots on the hinge 34a, the lock slider 33, which is combined with the operation lever 34 as one body, correspondingly does the rectilinear motion, while rotating at the same time, along the bottom surface 32b of the movable gear. In this way, the movable gear 32 is either locked to the fixed gear 31a or disengaged from the fixed gear 31a, thereby adjusting the steering column 11.
However, since the lock slider and the operation lever are combined with each other, the assembling work associated with these two components with complicated structures is often difficult. Also, if someone wants to change one of them, he has to change both of them, spending unnecessary cost.
Moreover, the lock slider requires more space to do the rotational motion. Taking apart the unnecessary space required, the lock slider can hurt the driver while rotating.
Another defect of the related art tilt steering apparatus is that although the operation lever is in a position for locking the movable gear, if the operation lever 34 rotates more or less than it is supposed to in the locking position because of a minor error in the manufacture of components, or if the operation lever 34 rotates, the lock slider 33 combined with the operation lever 34 correspondingly rotates and at the same time does the vertical rectilinear motion. As a result, the bottom surface 32b of the movable gear and the lock slider 33 make a point contact, not a line contact, and thus the supporting rigidity and the abrasion resistance of both components are deteriorated.